Well packer



G. GREEN WELL PACKER May 6, 1952 Filed May 23, 1947 as e 2 SHEETSSHEET l INVENTOR. George Green ATTORNEYS y 6, 1952 G. GREEN 2,595,573

WELL PACKER led May 25, 1947 2 SHEETS--SHEET 2 2 43 k i4 I723; 52

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INVENTOR. George Green ATTORNEYS Patented May 6, 1952 UNITED STATES WELL PACKER George Green, Houston, Tex.

Application May 23, 1947, Serial No. 749,992

4 Claims. 1

This invention relates to new and useful improvements in well packers.

The invention has particularly to do with that type of well packer wherein a'pressure-fluid expansible, elastic skirt depends from the bottom of the packer and which has wall gripping means above the skirt for anchoring the packer in a tubular conductor.

One object of the invention is to provide a packer having improved means for holding the expansible skirt of an elastic packing member in retracted form, whereby the packer may be freely inserted in and moved longitudinally in a well casing or tubing and liquids adequately by-passed.

A further object of the invention is to provide a-boot or retainer for holding said skirt in a retracted form, adapted to be slipped over the expansible skirt of a packing member and to be held thereon solely by frictional engagement, whereby said boot or retainer may be displaced downwardly by a pressure fiuid, to release said skirt.

Another object of the invention is to provide a boot of the character described which is formed with a continuous and smooth outer surface and a bullnose bottom, whereby the packer may be freely run into. a casing .or tubing string and moved longitudinally therein without impedance by. side wall. obstructions and irregularities.

' Still another object of the invention is to provide a boot of the character described which is made of relatively thin or soft metal or other material which may be readily disintegrated by drilling or grinding.

.A construction designed to carry out the invention will 'be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

. Fig. 1 is a view, partlyin elevation and partly in section, of the upper portion of a packer with which my invention may be used.

Fig. 2 is a similar view of the lower portion of said packer, constructed in accordance with the invention, the boot being in place.

Figs. 3, 4 and 5 are transverse, sectional views taken on their respectivelines through Fig. 1,

Fig. 6 is a partial sectional view of one of the bow springs, .and

.Fig. 7.15 aviewpartly. in -elevation and partly ..in. .section, illustratinglthe packingskirtin sealing .position, the -boot having been displaced.

Since the upper portion of the packer asshown in Fig. 1, is subject to a wide variation in structure and is merely illustrative of the use of the invention, I have. selected the form shown in my co-pending: application, Serial No. 620,710, filed October 6, 1945, now Patent No. 2,547,387, granted April 3,.1951.

In the drawings, the'numeral 10 designates generally a cylindrical housing of substantially uniform external diameter and including an upper or head section I l and a lower or slip section I2. At its lower. end, the section 1| is provided with an internallyscrew-threaded taperedsocket I3 into which is screwed a tapered screw-threaded pin l4 formed uponthe upperend' of the, slip section I2, which pin is provided with an annular shoulder 15 at its base engaging the lower edge of the member ll so as to provide a tight joint. The housing If] is tubular and a tubular slip mandrel, indicated generallyby the numeral I6, is slidable therein.

At its medial portion, which iswithin the section l2, themandrel is formed'on its outer surface with upwardly and inwardly inclined annular expansion rings I9 which are integral therewith and'are disposed vertically in stepped order. The lower end of the lowermost ring is surrounded-by an annular stop shoulder 20. The section 12 is'formed with vertical windows 2| spaced equi-distant in the circumference of said section, three of such windows being shown, but the numberbeing optional. .Vertical slips 22 are disposed-in these windows and each slip has upon its rear face inclinedsurfaces 23 complementary to the rings and engaging the same so that upon vertical movement of the mandrel the slips may be expanded and retracted. The inclined faces 23 are of such lengths. as to. permit vertical movement of the rings with respect to such surfaces. The slips are provided with vertical rows of teeth 24 for engaging the inner surface of a well pipe. When the mandrel is in its lowermost position, the teeth of the slips will. be retracted within the external diameter of the section l2 and when the mandrelis moved upwardly, the ringsv 23 will cause the slips to be radially expanded out through the windows 2|, whereby the teeth 24 will bite into the inner surface of a well pipe and fasten the packer in position. For limiting the outward or radial movement of the slips, each one is provided at its upper end with an inwardly directed recess 25 for receiving ,the lowerv end of a keeper 26 countersunk in thesurfaceof the section l2 at the upper end of. its respective window and.;.secured by a machine" screw '21. {Eachslip-has a depending lug 28 at its lower end co-acting with the keeper to limit the outward movement of the slip.

A tubular operating mandrel 30 is disposed to slide vertically in the head section I I. The head section is formed with counterbores 3|, 32 and 33, each of reduced diameter, upwardly of said section. The upper end of the section is formed with a short bore 34 in which the mandrel 30 is slidable. Elongate vertical splines 35 are provided on the mandrel and engage in vertical guideways 36 in the bore 34, whereby the mandrel 30 is free to slide vertically. The splines are long enough to remain in the guideways at all vertical adjustments of the operating mandrel, so that rotation may be contributed to the housing section II upon rotation of said mandrel. The upper end of the mandrel extends above the housing In and is provided with a screw-threaded pin 31 for attachment to an operating pipe (not shown).

The lower end of the mandrel 30 is formed with an annular externally screw-threaded head 38 having an overhanging annular flange 39 at its upper end. A fluid-pressure sealing ring 45 is fitted around the head and engages under the flange. An internally screw-threaded collar 4% is screwed onto the head below the ring and has ports 42 which register with radial ducts 43 extending transversely through the head from the bore of the mandrel 30. It will be noted that the upper end of the packer mandrel [6 has an annular neck 44 which has a sliding fit in an axial bore 45, formed in the upper end of the section !2. Within the'pin [4, an internal, annular recess 46 is provided for receiving a fluid-pressure packing ring 41 which snugly engages the neck 44 to form a fluid-tight joint.

The head 38 including the elements carried thereby, is of such external diameter as to have a sliding fit when moved upwardly into the counterbore 32. With the parts in the position shown in Fig. 1, it will be observed that fluid flowing in the bore of the mandrels l6 and 30 is free to escape through the ducts 43 and ports 42 into the counterbore 3| and thence upwardly through the counterbores 32 and 33, from which latter it may escape through radial ducts 48 into the pipe or tubing surrounding the packer. These elements form a by-pass and a by-pass valve, whereby the packer may be lowered or vertically adjusted in fluid in a well pipe. When the mandrel 30 is moved upwardly, the ring 40 will seal against the annular wall of the bore 32 and thereby shut off the by-pass. It will also be observed that the head 38 of the mandrel may be engaged with the neck 44 of the mandrel 16 to force the same downwardly and thereby permit the slips 22 to retract.

In order to prevent the housing ID from moving downwardly independently of the mandrel 30, whereby the mandrel l6 would be separated therefrom and the slips 22 inadvertently set, I provide a plurality of retarding elements in the form of elongate fiat springs 49 disposed in complementary recesses 50 in the surface of the section 12 between the windows 2|. The upper ends of these springs are fastened by screws I. These springs are bowed so that their medial portions will project outwardly from the outer surface of the housing and ride upon the inner annular surface of the well casing, while their lower ends are free so that said springs may be depressed into said recesses and yield to irregularities in the casing surface.

The upper packer portion described is suitable for use with the present invention. However, other securing means may be used with advantage. In applying the invention to the described upper portion of the packer, the enlarged lower end 52 of the mandrel I6 is formed with a tapered, internally screw-threaded counterbore 53 into which is screwed the tapered pin 54 of a mandrel extension 55 which has a bore of substantially the same diameter as the bore of the mandrel I6; thus there is, in effect, a continuous mandrel or conductor extending axially through the packer.

At the base of the pin an annular head 56 encircles the mandrel 55 and has a depending annular flange 5'! at its outer margin; said head being of substantially the same diameter as the housing in. The inner annular wall 58 of the flange is inclined to snugly receive the upper, truncated end 59 of an annular tubular packer sleeve 60 which has substantially the same external diameter as the head and is telescoped by the lower end of the mandrel 55. The lower half of the sleeve is formed into an annular skirt 6|, having its inner wall inclined downwardly and outwardly, so that the skirt is gradually reduced in thickness toward its lower annular end.

At the upper end of the skirt, the sleeve is provided with an annular lip 62 surrounding the bore of the sleeve and spaced inwardly from the skirt, whereby an annular space or groove 63 is formed around said lip. A supporting collar 64 is secured around the mandrel for receiving the lip which is loosely confined by an annular, upstanding flange 65 on the margin of the collar. The adjacent faces of the lip and the flange are parallel and inclined inwardly and downwardly with a small annular space therebetween. The collar and flange being spaced from the skirt and the lip being spaced from the flange, the upwardly flowing well fluid will exert its pressure against the lip and seal it around the mandrel. The head 55 and the collar 64 act to hold the packer against longitudinal displacement on the mandrel. The packer sleeve may be formed of any suitable soft flexible material, such as neoprene or other synthetic rubbers and the like.

A cylindrical boot or retainer 65 is slipped onto the skirt 6! of the packer sleeve. This boot preferably has a bullnose bottom 61 merged into its cylindrical wall so that the boot will freely pass through casing or tubing collars and ride over other side Wall obstructions. The boot is made of relatively thin material, preferably of metal, such as aluminum, brass and the like, or it may be formed of other material such as a hard plastic. The boot material should be of material which will readily disintegrate when drilled or ground and the term drillable as used herein is intended to mean such a material.

The internal diameter of the boot is less than the external diameter of the skirt 6| and is such that when the skirt is telescoped into theupper open end of said boot, the elastic material will be compressed or deformed, whereby the outer surface of the boot will be substantially flush with the outer surface of the upper portion of the packing sleeve.

However, the sleeve may slightly overhang the boot or the boot may protrude slightly beyond the outer surface of the former. In applying the boot a suitable tube or band (not shown) is slipped over the skirt to deform it sufliciently to slip the boot onto the said skirt, after which the ring may be slid upwardly and removed from k the sleeve.

The bullnose 61 of the boot is provided with a central opening or hole 68 which is considerably less than the internal diameter of the mandrel 55. When a fluid, such as oil or water or mud is pumped down the tubing and through the mandrel into the bullnose 61 of the boot, which extends below the skirt 6|, a back pressure and/or hydrostatic head will be built up in the boot, adequate to overcome the frictional engagement of the boot around the skirt and displace said boot downwardly, whereby the skirt will be released and permitted to expand to the position shown in Fig. 7. The back pressure or hydrostatic head will result because of the restricted diameter of the opening 68.

When the boot is displaced it will fall to the bottom of the well hole and may be disintegrated in a subsequent drilling operation. The boot may be cheaply made and no other elements, such as shear pins, screw-threads, or machining is required. When the boot is filled with a pressure fluid, the lip 62 will be subjected to such pressure and effectively sealed around the mandrel, and at the same time, said fluid pressure will tend to force the packer sleeve 66 lightly into the head 56.

In using the packer, the boot {-36 is frictionally engaged on the skirt, as hereinbefore described,

whereby the skirt BI is retracted and confined as shown in Fig. l. The pin 31 is secured to a string of tubing (not shown) and the packer is lowered into the casing or tubing. The diameters of the housing It), the sleeve and the boot are such as to leave an annular space therearound which is sufficient to by-pass fluid. Since the skirt cannot be expanded by the well fluid, the by-passes 42, 43 and 48 may be omitted if desired.

When the packer has been lowered to the selected location and the tubing is stopped and raised so as to lift the mandrel 30, the springs 49 serving to hold the balance of the packer in position. A suitable liquid under pressure is forced down the well tubing through the mandrels 30, i5 and 55, a portion of this liquid being discharged through the hole 68 of the boot 66 while the remaining portion fills the boot and the space within the skirt 6|. Such remaining fluid being under pressure will fill the space 63 and force the lip 62 into sealing engagement with the mandrel 55. This fluid pressure will also tend to force the truncated end 59 of the sleeve 68 more firmly into the head 56. This will prevent fluid escaping upwardly from the sleeve.

The pressure retained in the boot will build up a back pressure which exerts sufficient downward pressure on the bullnose bottom 6'! to displace the entire boot downwardly from the skirt 6|, whereby said skirt will be released and readily expanded into sealing engagement with the casing wall C, as is shown in Fig. '7. When the skirt is expanded, the pressure of the liquid will move the sleeve 60, head 56 and mandrel l6 upwardly, whereby the inclined rings !9 will expand the slips 22 and anchor the packer.

Since the boot 65 is formed of drillable material and is relatively thin, it may be disintegrated in a subsequent drilling operation. Due to the smooth annular wall of the boot and the bullnose bottom 6?, the packer may be readily passed through close annular obstructions and rapidly lowered in a well casing. The bullnose will guide the packer through collars and over 6 rough spots. While the hole 68 is desirable it maybe omitted. The invention may be used in connection with well cementing, acidizing, testing and for other purposes.

The term packer body as used herein includes the housing I0 and the mandrel l6 and its rings l9; while the term support may be applied to the mandrel 55.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. The combination with a well packer having anchoring slips and means for expanding and retracting the slips and a tubular mandrel depending from the packer, of an elastic sleeve carried on the mandrel, an outer elongate annular elastic skirt formed integrally with the sleeve and depending therefrom, the skirt being flared outwardly and downwardly from said sleeve when in normal unfettered position, a short annular internal elastic lip depending from the sleeve and closely embracing the mandrel below the sleeve, the short lip being formed integrally with the sleeve and being spaced radially inwardly from the skirt to form an annular groove at the bottom of the sleeve between the skirt and the lip, a flanged collar carried by the mandrel adjacent the lower end of .the lip, said collar having an upwardly extending marginal flange extending into the groove between the skirt and the lip, and a removable retainer frictionally engaging around the skirt to releasably hold said skirt in retracted fettered position.

2. The combination with a well packer having anchoring slips and means for expanding and retracting the slips and a tubular mandrel depending from the packer, of an elastic sleeve carried on the mandrel, an outer elongate annular elastic skirt formed integrally with the sleeve and depending therefrom, the skirt being flared outwardly and downwardly from said sleeve when in normal unfettered position, a short annular internal elastic lip depending from the sleeve and closely embracing the mandrel below the sleeve, the short lip being formed integrally with the sleeve and being spaced radially inwardly from the skirt to form an annular groove at the bottom of the sleeve between the skirt and the lip, a flanged collar carried by the mandrel adjacent the lower end of the lip, said collar having an upwardly extending marginal flange extending into the groove between the skirt and the lip whereby the lower extremity of the lip is protected against pressure fluid present between the lower portion of the mandrel and the interior of the skirt, and a releasable cylindrical boot engaging around substantially the entire length of said skirt to releasably hold said skirt in retracted fettered position, said boot having a bullnose bottom.

3. The combination with a well packer body having anchoring slips, of a tubular mandrel carried by the body, an elastic sleeve secured around the mandrel, an annular elastic skirt depending from the sleeve and spaced from said mandrel, an annular elastic lip dependnig from said sleeve at and within the upper end of the skirt and around said mandrel, a flanged collar surrounding said mandrel and loosely receiving the lip, whereby said lip is exposed to a pressure fluid received within said skirt, and a removable re- I tainer adapted to be moved upwardly and frictionally engage around said skirt.

4. The combination With a well packer body having anchoring slips, of a tubular support carried by the body, an elastic packing sleeve surrounding the support, means for holding the sleeve around said support, a long annular elastic skirt depending from said sleeve and spaced from said support throughout its length, and a boot frictionally and removably engaging around substantially the entire length of said skirt and having a bullnose bottom.

GEORGE GREEN.

8 REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS 

